The present invention relates to low-depth, nestable trays for transporting beverage containers, such as aluminum cans.
Beverage cans are often stored and transported during the distribution stages in short-walled carboard boxes or in reusable, lightweight plastic trays intended to supplant such boxes. One such form of plastic tray is shown and described in U.S. patent application Ser. No. 07/369,598, filed Jun. 21, 1989 by the Applicant hereof and assigned to the Assignee hereof, the contents of which patent application are hereby incorporated herein by reference.
While the plastic tray device embodied in application Ser. No. 07/369,598 constitutes a significant improvement over short-walled cardboard boxes, the invention described herein improves upon the design of such tray in overcoming certain disadvantages prevalent in the use of low-depth plastic trays. For example, in the shipment of trays filled with cans, when large numbers of such trays are deposited in layers on pallets for ultimate transfer to transport apparatus, the trays are arranged in close side-by-side and end-to-end relation on a palletizing device positioned above the pallet to receive the layer of trays. In practice the trays are disposed on a floor panel of the palletizer, which panel is adapted to be withdrawn so that the trays supported thereon will be caused to drop a slight distance onto the underlying pallet or previously deposited tray layer thereon. Because the panel is withdrawn from one end to the other of the supported set of trays, as the panel moves out from under each tray, or line thereof, the trays will fall in sequence. The weight of the can load borne by each tray prevents their being dropped in perfect parallelism onto the surface below. Instead, the weight of the load tends to move the falling tray slightly such that it tends to move in the direction of the previously passed tray whereby the rail forming the side structure of the falling tray is caused to land on, and thus be retained by, the upper edge or rim of the rail of the adjacent tray. This overlapping of adjacent trays causes one end of the tray to be raised with respect to the other and is commonly referred to as "shingling". Shingling, it will be appreciated, is disruptive of load stability on the pallet since it initially prevents the achievement of a perfectly squared load. Subsequently, moreover, disengagement of the shingled trays, as for example when the palleted loads are being transported, creates a change in load configuration and perhaps even a load shift, both of which are undesirable.
Another problem addressed by the present invention occurs as a result of stacking empty trays in nested relation. Due to the fact that the side structures of the trays have a general configuration of being upwardly divergent, particularly because of inwardly extending, inclined columns that are spaced about the periphery of the tray to supportively space the side structure rail from the tray floor when a great number of trays are nested to create a high stack, those trays positioned toward the bottom of the stack are subjected to substantial compressive loads. Such loads, it will be appreciated, create a tendency of the sides of the compressively loaded trays to spread thereby permitting the overlying tray to be pressed downwardly into the subjacent tray. With the nested trays so-compressed there is, at best, a difficulty created in separating the trays at time of use. At worst, the trays, being formed of light weight plastic material, can become damaged.
Still another problem addressed by the invention is the potential damage to the fluid containers that are thin-walled numbers formed of a relatively fragile material, such as aluminum. In trays of the "low depth" type a recurring problem is that any tipping of the containers standing immediately adjacent the side structure of the tray can, when the container wall impacts on the side structure, impart an impact force on the former that may result in denting, dimpling or creasing of the container wall. Also, when the containers are subjected to vibration against the tray side structure over an extended period, it is conceivable, in the worst case, that a hole can be produced in the container wall. In a less severe case, the graphics on the container wall can be obliterated due to the erosive effects of the vibration.
It is to the amelioration of these problems, therefore, to which the present invention is directed.